Chapter 19 Muscle

Which of the following structures plays the largest role in cerebellar-cortical "closed loop" circuits? a. Dentate nucleus b. Interposed nucleus c. Fastigial nucleus d. Peduncular nucleus e. Accessory dorsal column nuclei

a. Dentate nucleus

The _______ cell is the cell type that is the main output from cerebellar cortex and is considered its prime computational element. a. Purkinje b. granule c. Golgi d. basket e. stellate

a. Purkinje

Which of the following statements about recalibration of the VOR is false? a. The VOR is precisely recalibrated with each eye movement so that perfect fixation can be maintained during head rotation. b. The cerebellum is involved in adjusting the VOR when eye movements do not properly compensate for head rotation. c. The cerebellum integrates visual information, vestibular information, and motor information (efference copy) when performing recalibration. d. In the absence of the cerebellum, the VOR could not be recalibrated. e. All of the above statements are true, none is false

a. The VOR is precisely recalibrated with each eye movement so that perfect fixation can be maintained during head rotation.

The part of the cerebellum that is highly developed in humans and involved with the planning and execution of complex spatial and temporal sequences is the a. cerebrocerebellum. b. spinocerebellum. c. vestibulocerebellum. d. flocculus. e. nodulus.

a. cerebrocerebellum.

Which of the following statements about the reeler mutation in mice is false? a. The name reeler was given based upon its impaired locomotor abilities. b. Because of induced genetic abnormalities, it was impossible to determine which chromosome contained the reeler mutation. c. A "synthetic" reeler mutation was discovered by chance after inserting DNA marker fragments into the mouse genome. d. The mutation appears to interfere with the extracellular matrix in the cerebellum. e. In reeler mice, the Purkinje, granule and other cell types are found in incorrect locations in the cerebellum.

b. Because of induced genetic abnormalities, it was impossible to determine which chromosome contained the reeler mutation.

Which of the following statements about the cerebellar Purkinje cell is false? a. Its dendritic field branches in a narrow plane. b. Its dendritic field is oriented parallel to the parallel fibers. c. Each one is contacted by roughly 200,000 granule cells. d. Purkinje cells project to the deep cerebellar nuclei. e. Purkinje cells inhibit deep cerebellar nuclear cells.

b. Its dendritic field is oriented parallel to the parallel fibers.

Which part of the cerebellum receives input directly from the spinal cord? a. Cerebrocerebellum b. Spinocerebellum c. Vestibulocerebellum d. Flocculus e. Nodulus

b. Spinocerebellum

Which of the following did not lead to, nor help confirm, the theory that a proteinaceous agent or prion causes such diseases as scrapie and "mad cow" disease? a. The occurrence of a scrapie-like disease among New Guinea cannibals b. The extreme sensitivity of the agent to UV light c. Affinity chromatographic purification of a prion infectious agent d. Inherited spongiform encephalopathies in humans e. Resistance in mice with a null mutation in PrPc (prion protein control)

b. The extreme sensitivity of the agent to UV light

The large size of the cerebral peduncles in the midbrain is related to cerebellar inputs a. arriving through the superior cerebellar peduncles. b. arriving through the middle cerebellar peduncles. c. arriving through the inferior cerebellar peduncles. d. projecting to the vermis. e. projecting to the vestibulocerebellum.

b. arriving through the middle cerebellar peduncles.

During electrical recordings from cerebellar neurons, flipping the wrist back and forth a. elicits the firing of Purkinje cells and deep cerebellar neurons in alternation. b. leads to neuronal responses associated with relaxation or contraction of specific muscles and changes in joint position and movement direction. c. initiates a repeating sequence of activation: from granule cells, to Purkinje cells, to stellate cells, to deep cerebellar neurons. d. initiates a repeating sequence of activation: from Purkinje cells, to basket cells, to stellate cells, to deep cerebellar neurons. e. None of the above

b. leads to neuronal responses associated with relaxation or contraction of specific muscles and changes in joint position and movement direction.

In the weaver mutant strain of mouse, the defect associated with ataxia, hypotonia, and tremor is a. the disappearance of the cerebrocerebellum. b. a complete lack of Purkinje cells. c. a marked lack of granule cells. d. misplaced cells in cerebellar cortex due to an extracellular matrix deficit. e. a cerebellum shrunk to half its normal size, albeit with normal cellular architecture.

c. a marked lack of granule cells.

Alcohol-induced damage to the vermis of the cerebellum has been associated with a. chronically slurred speech. b. word-finding difficulties. c. a wide and staggering gait. d. inability to perform fine movements of the hands and fingers. e. impaired judgment.

c. a wide and staggering gait.

Mossy fibers synapse on a. Purkinje cells and deep cerebellar nuclei. b. Purkinje cells and granule cells. c. granule cells and deep cerebellar nuclei. d. deep cerebellar and pontine nuclei. e. Golgi, basket, and stellate cells.

c. granule cells and deep cerebellar nuclei.

The axons from the pontine nuclei into the cerebellum are referred to as _______ fibers. a. parallel b. basket c. mossy d. stellate e. climbing

c. mossy

The cell bodies that give rise to the largest number of fibers entering the cerebellum are located in the a. cerebral cortex. b. cerebellar cortex. c. pons. d. medulla. e. superior colliculus.

c. pons.

Which of the following is not one of the deep cerebellar nuclei? a. Dentate nucleus b. Interposed nucleus c. Fastigial nucleus d. Peduncular nucleus e. All of the above are deep cerebellar nuclei.

d. Peduncular nucleus

The _______ cells make an "inhibitory nest of synapses" with the Purkinje cell bodies. a. granule b. stellate c. Golgi d. basket e. All of the above

d. basket

Cerebellar ataxia is characterized by a. difficulty with initiating movements. b. an inability to perform goal-directed movements. c. an inability to perform complex sequences of movements. d. jerky, imprecise movements. e. All of the above

d. jerky, imprecise movements.

Which is thought to be the role of the climbing fiber input to the cerebellar cortex? a. Summation of motor errors from different sources b. Provision of a difference error between two sources c. Making fast online adjustments of ongoing motor patterns d. Gradual correction of motor errors over many trials e. Provision of a training signal for the parallel fiber synapses onto Purkinje cells

e. Provision of a training signal for the parallel fiber synapses onto Purkinje cells

The distinct T-shaped parallel fibers emanating from the granule cells were shaped by evolution to a. calculate motor error signals. b. sequence complex motor programs. c. perform center-surround inhibition like calculations. d. transform sustained pontine nuclear signals into transient motor commands. e. do things that we still do not understand.

e. do things that we still do not understand.